diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2018-01-10 03:07:15 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-16 20:09:35 +0100 |
| commit | 8dd311f1ec740b05c851d65bab9cfdde26e35a8a (patch) | |
| tree | c35f3f8feedf33beb1f9f9642f988d4a20160396 /arch | |
| parent | 9bfecafe84e628c5dff9cbeaa4b6e73560adb925 (diff) | |
powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
commit b8e90cb7bc04a509e821e82ab6ed7a8ef11ba333 upstream.
In the syscall exit path we may be returning to user or kernel
context. We already have a test for that, because we conditionally
restore r13. So use that existing test and branch, and bifurcate the
return based on that.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 8efd8c402cf7..2837232bbffb 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -230,13 +230,23 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) ACCOUNT_CPU_USER_EXIT(r11, r12) HMT_MEDIUM_LOW_HAS_PPR ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ + ld r2,GPR2(r1) + ld r1,GPR1(r1) + mtlr r4 + mtcr r5 + mtspr SPRN_SRR0,r7 + mtspr SPRN_SRR1,r8 + RFI_TO_USER + b . /* prevent speculative execution */ + + /* exit to kernel */ 1: ld r2,GPR2(r1) ld r1,GPR1(r1) mtlr r4 mtcr r5 mtspr SPRN_SRR0,r7 mtspr SPRN_SRR1,r8 - RFI + RFI_TO_KERNEL b . /* prevent speculative execution */ syscall_error: |